Conservation and Restoration Biology
the issues
Conservation Biology
A value-laden science
Human Impacts – An Overview
Human Impacts – An Overview
• Humans consume:
– 35% of the productivity of
ocean shelves
– 60% of freshwater run-off
– ~30% of global net primary
productivity
Extinction
Extinction – the last member of a species dies and the species
ceases to exist – a global loss!
Extirpation – the disappearance from a given area (local
extinction)
Past Mass Extinctions
• 5 mass extinctions in the past during which ~50-95% of
species went extinct
• Diversity levels eventually recover to pre-extinction levels
One
projection of
extinction
rates
Human Activities
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Habitat loss and degradation
Overexploitation
Pollution
Introduced species
Climate change
Habitat loss
Habitat loss
• Causes
– Clearing for
agriculture
– Grazing
– Development
– Subsistence
(firewood, etc.)
Land cover change due to the
building of the Itaipu Dam and
conversion from forest to soybean
fields (Argentina)
Oculina Reef before and after bottom trawling
Habitat loss
• Effects
– Change in carbon cycle –
Amazon is now a source
rather than a sink
– Change in hydrology –
flow rates
– Change in available
habitat
Causes of habitat degradation
Solid Wastes
• Plastics
Cause tangling
Can be ingested
Don’t biodegrade
Causes of habitat degradation
Agriculture
Agricultural land use has increased over time
• 265 million hectares (1700)
• 1.2 billion hectares (1950)
• 1.5 billion hectares
(currently)
• 98% of arable land
transformed
Causes of habitat degradation
Agriculture
• Dark areas = at least 30% of landscape is cultivated
Causes of habitat degradation
Extraction
Includes:
Mining
Logging
Oil drilling & refining
Fishing
Causes of habitat degradation
Extraction
Causes of habitat degradation
Urbanization
Las Vegas, Nevada
Causes of habitat degradation
Pollution
• Can lead to habitat loss
• Forms include:
• Light pollution
• Air pollution
• Acid rain
• Solid, plastic waste
• Toxic chemicals
Pollution
Overexploitation
Snail invasion in Hawaii
• Giant African Snail introduced as a garden
ornamental – by 1955 was considered a
pest
• HI Dept. of Agriculture introduced 15
predatory snails to control it (3
established)
Snail invasion in Hawaii
• The rosy wolfsnail had minimal impact
on the African snail, but decimated the
population of endemics
• 15 out of 20 species became extinct
• Introduced to 20 other islands – in the
Society Islands 56/61 endemics
became extinct
Unintentional
Intentional
Why should we care?
Conservation Paradigms:
• Non-utilitarian – Species have an intrinsic
value
• Utilitarian – Species/communities are
important because they have an economic
value
Utilitarian argument • Costanza et al. (1997) calculated that the value
of natural intact ecosystems is ~ USD 33
Trillion, because of the services they provide
• Global GDP in 1997 (USD 18 Trillion)
Ecosystem Services
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Gas Regulation – O2/CO2, O3
Water supply and regulation
Soil formation
Nutrient Cycling
Pollination
Raw materials
Recreation
Mitigation
• Conservation Biology
• Restoration
• Sustainable Growth
Conservation
• Types of Rare Species
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Size of population
Specialization of habitat
Extent of distribution
Not all rare species are threatened
• Classifying conservation status
– Type of threat
– Viability analysis (Is it healthy?)
» Size of population
» Variation in population
» Demographics
Conservation
• Approach
- Single species
- Ecosystem/Community
- Establishing protected areas
- Create conservation goal
- Reserve size
- Connectivity
- Management
- Edge communities
Mitigation
• Conservation Biology
• Restoration
• Sustainable Growth
Effective Restoration
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Setting goals
Degrading processes identified
Reverse degrading processes
Incorporate restoration into management
strategies
• Management/ monitoring
• Stakeholder input
Examples of restoration projects
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Removal of invasive species
Mine site reclamation
Vegetation
Controlled burns
Reintroduction of “rivet” species
Buffer strips
Science based
Invasive Species
Removal
Examples of restoration projects
• Mine site reclamation
• Revegetation
Examples of restoration projects
Controlled burns
• Reintroduction of “rivet” species
• Buffer strips
• Science based
Examples of restoration projects
• Buffer strips